History of Crestfallen

Crestfallen is a Supremacy triumph: in a single life, create five consecutive crests that are secured by your teammates.

How to complete

1. In Supremacy, defeated players drop a crest; a kill adds 1 point and collecting an enemy crest another. Teammates must pick up the crests from your kills.
2. Stay alive for five kills in a row whose crests are collected, so play close to teammates and let them collect.

It is listed as Rare and was added in Season 4. Supremacy is in the Destiny Content Vault, so availability depends on events.